Figure 12The outside border of the ring with 210 sites and the inside border of the ring with 545 sites. These boundaries are two chains of sites, one with heptagonal sites (green) separated by one or two hexagonal sites (red) having 55 sites, the other with pentagonal sites (blue) separated by hexagonal sites (red) having 89 sites. Starting from the first green site (cross) and rotating as indicated by arrows, we can describe a chain as a succession of long (l) or short (s) segments. Starting from the first blue site (cross) there is also a chain rotating in the reverse orientation. Both chains are related by an inflation symmetry.